Its all safe as far as I know. I use the branches for my other animals, funny shaped twigs that roll nicely for the rabbits, and the flowers for the rabbits. Ive just never bothered to use the leaves. Also if youre looking at using the wood, what type of bark does it have? We have a large bush but it has rough bark so I would strip the bark off that one, however some bushes like my neighbours that I frequently chop up *cough* has very smooth bark and I leave the bark as is.